I also have me reading the bible the Palm Sunday here it is:
We celebrate Palm Sunday because Jesus came on a donkey colt. Jesus told his disciples to go and get the donkey colt and if anyone asked them why they were supposed to say that the Lord needs it. When he came riding on the donkey, the people put their blankets on the ground to celebrate. They were excited about him coming and they were saying "Hosanna!" They knew he was coming to save them but they thought it was in a different way.